This kit is a portable stamp battery, much smaller than those used in large permanent stamp mills. It is a 3-stamp prospecting mill made by Fulton Engineering and Shipbuilding Works of San Francisco. It is designed to be easily taken apart for transportation. The kit includes 33 white metal castings, wood strips, and wire with complete instructions for assembly and operation. Large mill stamp batteries were assembled on site. This portable stamp battery could be pre-assembled and shipped on a flat car, making an interesting load.